ERCoCr-E Flux-Cored Wire (Cobalt Alloy 21 Gas-Shielded / Open-Arc Hardfacing Wire)

1. Description & Applications

ERCoCr-E Flux-Cored Wire is a tubular composite hardfacing wire that deposits a low-carbon, solid-solution-strengthened cobalt-chromium-molybdenum alloy equivalent to Stellite 21. By utilizing molybdenum for matrix strengthening rather than tungsten, this alloy offers exceptional impact resistance, thermal shock resistance, and high ductility while maintaining excellent resistance to high-temperature oxidation, corrosion, and metal-to-metal wear up to 800°C (1472°F). It features a prominent work-hardening characteristic, allowing the weld deposit surface to harden under repeated impact or compressive loading.

Key Applications:

• High-temperature and high-pressure valve seats, discs, and gate valves

• Hot forming dies, forging tools, and shearing blades subject to severe thermal fatigue

• Steam turbine components, pump shafts, and fluid-handling equipment

• Continuous casting rolls and components exposed to mechanical and thermal shock

2. Nominal Chemical Composition of Weld Deposit (wt%)

3. Mechanical & Deposit Properties (As-Welded)

• Hardness (As-Welded): 27 – 40 HRC (lower initial hardness for maximum impact toughness and crack resistance)

• Work-Hardened Hardness: Up to 48 HRC under dynamic impact and mechanical wear

• Thermal Shock & Impact Resistance: Outstanding; superior crack resistance compared to high-carbon cobalt flux-cored wires

• Machinability: Good; readily machinable compared to tungsten-bearing hardfacing alloys due to its lower carbon content

4. Recommended Welding Parameters (FCAW-G / Gas-Shielded)

• Shielding Gas: 80% Argon + 20% $\text{CO}_2$ (or 100% Argon depending on application), Flow rate: 15–25 L/min

• Current Type: DCEP (Direct Current Electrode Positive)